The present invention relates to irrigation controllers and, more particularly, to solid-state electronic controllers used for the sophisticated control of irrigation systems.
Controlled irrigation of large turf areas is a complicated matter. While it is possible to accomplish the function manually, this mode of operation is highly consumptive of time both as to duration and in man hours. Through the years, as technology increased, the function has been transferred to automated control systems. The area to be irrigated is provided with a network of underground piping with strategically placed sprinkler heads connected thereto. Various branches of the system are controlled by interposing solenoid operated values between the branch and the source of pressurized irrigation water.
In the copending United States Patent Application No. 866,049, U.S. Pat. No. 4,165,532, entitled "Automatic Irrigation Sprinkler System Controller" by T. L. Kendall et al, assigned to the common assignee of this application, a solid-state irrigation controller is disclosed employing a number of features heretofore unavailable in such controllers. The controller disclosed therein is well-adapted for its particular scope of use and the specific teachings of the application are incorporated herein by reference.
The controller of said application is limited to a mid-range usage. That is, the features and, therefore, the attendant cost are such as to make it more sophisticated and costly than the normal homeowner might be readily willing to pay for. On the opposite end, the output capability is not sufficient for very large-scale turf applications such as found in the control of irrigation systems for golf courses and the like.
Golf courses, in particular, provide a unique environment for irrigation control. A syringe mode must be provided to allow the groundskeeper to quickly prepare the course for daily play by, for example, eliminating the morning dew from the grass, which otherwise interferes with optimum playing conditions. The amount of ground being irrigated and, therefore, the number of branch lines is such that it is highly desirable to provide a centralized and easily accomplished means for cancelling an entire watering cycle in the event of rain and/or selectively providing irrigation in areas requiring additional water without overwatering other areas. What is required is a large-scale system which can be readily modified by a groundskeeper to conform the irrigation being accomplished to the ever-changing requirements of the landscape.
Wherefore, it is the object of the present invention to provide such a large-scale irrigation control system having a high degree of flexibility while at the same time being simple to learn and easy to use.